Nutrition and Dietetics
The Nutrition and Dietetics domain covers nutrients, their functions and sources, recommended dietary allowances, deficiency diseases, balanced diets and therapeutic diets. Kerala questions are often calculation- or case-based: compute energy, identify a deficiency, or plan a diet for a condition.
Nutrients
- Energy: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g (1 kcal = 4.184 kJ).
- Protein: nine essential amino acids for adults; first-class proteins (egg, milk, fish) supply all, second-class (cereals, pulses) do not. Cereal–pulse combinations give mutual supplementation.
- Fat: essential fatty acids; carries fat-soluble vitamins A, D, E, K.
- Minerals: calcium, iron, iodine, zinc.
- Vitamins: fat-soluble (A, D, E, K) risk toxicity; water-soluble (B-complex, C) excess is excreted.
Deficiency diseases
Marasmus - energy and protein deficiency, under one year, wasting without oedema. Kwashiorkor - protein deficiency, 1–3 years, oedema, moon face, fatty liver. Vitamin A - night blindness, xerophthalmia. Vitamin D - rickets. Iron - microcytic anaemia. Iodine - goitre, cretinism.
Diet in disease
Diabetes: high fibre, low glycaemic index, regular meal timing. Hypertension: low sodium, DASH pattern, potassium-rich foods.
Worked example. A snack has 40 g carbohydrate, 8 g protein and 5 g fat. Energy = (40×4) + (8×4) + (5×9) = 160 + 32 + 45 = 237 kcal. Show each step; the method carries marks even if arithmetic slips.
Traps. RDA is a recommendation including a safety margin, not a minimum; do not swap kwashiorkor and marasmus; and fat-soluble vitamin excess is dangerous.